Speed-control apparatus for railway cars



c. A. RICHMOND SPEED CONTROL APPARATUS FOR RAILWAY CARS Original Filed Sept. 15. 1916 2 Sheets-Sheet l @c&. 2 1923.

C. A. RHCHMQND SPEED CONTROL APPARATUS FOR RAILWAY CARS Original Fild se t. 13

1916 2 Sheets-Sheet 2 mam/ran Q. g Mg Amm/m;

ih itititaid P A T lei CARL A. RICHMOND, OF NEW YORK, N. Y., ASSIGNOR TO THE GENERAL RAILWAY SIGNAL COMLPANY, A CORPORATION OF NEW YORK.

SPEED-CONTROL APPARATUS FOR RAILWAY CARS.

Application filed September 13, 1916, Serial No. 119,840. Renewed January 2. 1923.

To (ZZZ whom it may concern."

Be it known that I. CARL A. Ricnnonn, a .citizen of the United States. residing at New York city, in the county of New York and State of New York, have invented certain new and useful Improvements in Speed-Control Apparatus for Railway Cars. ofwhich the. following is a full, clear, and exact specification.

' The principal object of my invention is to provide new and improved apparatus for a railway car adapted automatically to Warn the operator or to check the speed of the car when another car on the same trackis approached at an unsafe speed. Another object of my invention is automatically to give warning or to control the speed. of a railway car both in accordance with the presence of another car on the track and in accordance with the requirements imposed by permanent track conditions. Still another object of my invention is to initiate the control of the car by approach to a car on the track ahead, to continue such control in accordance with the requirements imposed by local track conditions, and to relieve the car from such control when the departure of the car ahead makes it safe to do so. A further object of my invention is to divide the track into blocks, distribute ramps along each such block according to the local characteristics of the block, condition these ramps by a car ahead, and govern a following car by the ramps accordingly. These and other objects of my invention will be made apparent in the following specification and claims taken in connection with the accompanying drawings. In these drawings 1 have illustrated one specific embodiment of my invention. The invention is defined in the appended claims, and in exemplification thereof I now describe the apparatus disclosed in the drawings.

Fig. 1 is a diagram of the car-carried parts of an embodiment'of my invention;

Fig. 1 is an enlarged detail partly in section of a portion of the apparatus shown in Fig. 1;

Fig. 2 is a diagram of the track and associated apparatus to cooperate with the. car equipped as shown in Fig. l; and Fig. 3 is a diagrammatic view, similar to Fig. 2. showing a modified arrangement of trackway apparatus and circuits.

The track. whose left-hand rail head is 11 and right-hand rail head 12, is adapted t r one-way traffic. as indicated by th arrow 8. The rear axle l has its'left wheel '13 shown in Fig. l. and the front axle 10 has its right wheel it also shown. The, rear axle 9 drives a centrifugal governru' l) which carries a vertical bar 16. which in turn has a sliding coimection with another bar 17, the spring 18 tending to hold these two bars in elongated relation. (See Fig. l These bars 16 and 17 carry respective rollers 21 and 22 engaged by the wedge 19, which acts in opposition to the spring 18. The upper bar 17 carries a circuitcoir trolling member 20.

A lever 23 pivot-ed at 27 is held normally by the energized olenoid 33 against the ten sion of the spring 24. and its range of movement is limited by the stops 25 and 26. It carries a pin 29 in a slot 28 in the end of the rod 31 connected to the wedge 19. y

The rack bar 36 slides in a guide 35 on the. support 34 and is connected by a, link 37 to the lower end of the lever 23. An escapcment dog 38 engaging the rack 36 is held at one extreme by the spring 39 and is adapted to be rocked to the other extreme by the magnet 41.

By the front car wheel 14 on the support 42 is pivoted a shoe 4-3 held normally in the position shown in the drawing by the spring 44. As the shoe 43 rocks backward. it inoves the bar 1 5 up in the guide 16, thus opening or closing certain circuit controllers. There is A similar shoe. 43 on the left side of the ear opposite the wheel 13; this shoe 43 and its associated parts are designated by corresponding numbers with primes and are displaced to a part of the drawing where they can be clearly shown.

The solenoid 81 is normally energized and holds the head 82 against one stop 88, compressin the spring 83. When released, the spring 83 acts directly on the rod 31,

pushing the wedge 19 between the rollers 21 and 22 until the head 82 engages the other stop 88.

The control relay 6566 has two windings by either of which it may be energized, a direct current winding 65 and an alternating current winding 66, and in series with the latter is an impedance coil 67., The stop relay 90-91 also has a direct current winding 90 and an alternating current winding 91. The alternating current windings of these relays may receive current of high, medium or zero Voltage as will be pointed out later on. Because of the impedance 67 in series, only high voltage will SllfilCQ to make the coil 66 pick up or hold up its armatures, but either high or medium voltage will suffice to make coil 91 pick up and hold up its armatures.

Referring to Fig. 2, the track rail 11 is continuous but the rail 12 is divided into sections by insulators 51, thus forming blocks 52 52", 52, etc. Within each such block are ramps as 54 adapted to be engaged by the shoe 43. For convenience in the descriparrangement of the circuits, will be broughtout in the'following discussion of the mode of operation of this embodiment of my in "ention. As will appear hereinafter the ramps 54 are conditioned according to the location of a car ahead. When the car ahead is so far ahead that the ramps in a block are unaffectedthereby, that is, are in their normal condition, I refer to the block as clear; when the car ahead is in the block ahead, I refer to' the block behind that car as caution-controlled; and when the car is inthe very block considered, ll call that block danger controlled. Also when a car is inta caution controlled block behind another or in a danger controlled block, I refer to the car as being caution controlled or danger controlled as the case may be. As will be shown presently, caution control corresponds to release of solenoid 33 and danger control corresponds to release of solenoid 81. Furthermore, caution control may be referred to as of different degree, greater in degree according as the lever 23, after release by solenoid 33, has been stepped farther clockwise by spring 24 and succesgive oscillations of dog 38. The appropriateness of the use indicated for these terms will become apparent presently.

Case 1. Running within a clear block.

Assume that a car is about to enter the block 52 and that this block is clear. The

apparatus associated with the track will be in the condition shown in Fig. 2, and the apparatus on the car will be as shown in Fig. 1. The control relay direct current n'iagnet 65 will be energized, its circuit being traced through the armature 69 and the contacts 75 and 75 (circuit A). The energized magnet 65 not only holds up the armature 69 of circuit A, but also the armatures 70 and 71. Through the armature 70 a circuit is maintained through the green lamp Gr (circuit B), which apprises the operator of the car that he is running free from control by a car ahead. Through the armature 71 a circuit is maintained. through the solenoid 38 (circuit C), which holds the lever 23 against the stop 25. The stop relay direct current magnet 90 is energized through armature 92 and contacts 75 and 75 (circuit A), thus holding its armatures up as shownin Fig. 1. The ramps 54 approached by the car are supplied from the transformer secondary terminals 111 and 112 with high electromotive force (partial circuit D). For example, in the case of the first ramp 54, this partial circuit may be traced as follows: commencing at ramp 54', wire 1'50, relay 96, wire 151, back contact 99 of relay 97, wires 152, 153, 154 and relay 97, wire 155, back contact 102 of relay 97 associated with the next ramp 54 in advance, wires 156 and 157 back contact 102 of the next relay 97, wires 158 and 159, back contact 108-of relay 105, Wires 160, 161, and 162, front contact 100 of track relay 55. wires 163 and 164, secondary terminal 112 and wire 165 to the track rail 12. When the shoe 43 engages a ramp 54, the raising of the shoe 43 will close the contacts 79 and thus connect to the partial circuit D associated with the ramp 54 two partial circuits in multiple from the shoe 43 through the said contacts 79 and the respective alternating current magnets 66 and 91 (partial circuits E and E). The resulting flow of current through the magnets 96 and 97 in series associated with the ramp 54 will energize these magnets and cause them to attract their armatures 98, 99, 101 and 1.02. Thus, at 102, all the portion of the partial circuit D behind the car will be disconnected and left dead. The raising of the armature 98 closes a stick branch circuit through the magnet 97 and the impedance 104 to the track rail 11 (circuit D). After the shoe 43 leaves the ramp 54, the magnet 96 is deeiiergized and drops its armature 101, but the magnet 97 remains energized and holds u its armatures 98, 99 and 102. When the shoe 43 en ages the next ramp 54 ahead, the corresponting magnets 96 and 97 are men gized. and the consequent raising of the corresponding armature 102 cuts off the part of the artial circuit D to the rear and deenergizes the stick magnet 97 at the rear which thereupon drops its armature-s 98, 99 and 102.

lVhen the shoe 43 rises on the ramp 54. it opens at 75 the direct current circuits A and A for coils 65 and 90, but the high voltage alternating current flowing from the ramp 54 through the partial circuits E and E and energizing the alternating current magnets 66 and 91 causes them to hold up their armat-ures. Before the shoe -13 leaves the ramp 54, thus before the alternating current magnets 66 and 91 are deenergized. the shoe -13 lowers to a pointthat establishes the contact 75. whereby the direct currentmagnets 65 and 00 are again energized. Thus, it will be seen that while a shoe -13 engages a ramp 54 supplied with high electromotive force. the burden of sustaining the respective armaturcs ot' the control relay 6566 and the stop relay 9091 is transferred from the direct current magnets 65 and 90 to the alternating current magnets 66 and 91.

When the shoe 43 rises on the ramp 54. it closes the contacts 76, thus energizing the magnet 41 (ci-rcuit F) which roks the dog 38 to the right to be returned presently by the spring 39 when the shoe 43 leaves the ramp 54. This oscillation of the dog 38 is of no consequence at this time. because the lever 23 is held by the solenoid 33.

As the car proceeds in the block 52 each engagement of the shoe 43 with a ramp 51 produces the inconsequential eftects on the car as just described. and cuts 011' the part of the partial circuit D behind the car at the corresponding armature 102 and sticks up the circuit D through the corresponding armature 98 and impedance 104; also the ramp 54 engaged by the shoe 43 is killed as soon as the shoeleaves it, by the dropping of the armature 101.

It at any time the car attains a certain considerable speed. the speed responsive device 15 will depress the member 20, close. the contacts 62, and actuate the: Warning signal 1V (circuit J). This will signify to the operator that he has attained a proper speed. Further increase of speed will close contacts 63 (which are more widely separated than the contacts 62) and actuate warning signal V (circuit K), 'which is of ditl'erent. char-- acter from V and which will signify that the speed is too high a nd should be reduced. Still further increase of speed will open contacts 64 (which require still further movement of the member 20 before separating) and release the emergency brake device Ell (circuit L), which will apply the emergency brakes. The emergency brake device EB may be any one of the types well known in the art which will act --to give an automatic emergency application of the brakes when deenergized; for example. an elcctropneir matic valve capable of venting the train pipe at the emergency rate. 11' desired. li \v ever. a service appli ation of the brakes may be given instead of an emergency appli ation.

Following (use I. assume that a car in the clear block 52 reaches the ramp 5T-53 at the end of the block. l pon contact of shoe 43 with part 5.7 of this ramp. a current oi high electromotive force lows t'rom terminal 112 and armature 100 through the. two magnets 105 and 100 in multiple. In series with magnet 106 is an impedance 107. so that whereas either high or medium electromotlve force in 105 will raise its armature. only high in 100 will raise its armat-urcs. .\ccordingly under the conditions of this case. all the armatures will be picked up. and at 108 partial circuit D and stick circuit I) will be opened. permitting closure oi the armature 102 of the relay 9? next in the rear of said block 52*. The raising of armature 110 closes a stick shunt around armature 100. so that when the front wheels 14 enter b ock 52 and shunt magnet 55 causing it to drop its armature 100. nevertheless no change is made at this time in the current supply to ramp 5T-58. The raising of armature 109 comlnctively connects the two parts of ramp 5T58. so that until the shoe 43 leaves the part. 53. it receives high electromotive force from terminal 1 12. Finally when the shoe 4-3 leaves part 53 ot' ramp 57-58, the magnets 105 and 100 are dccnergized and drop their armaturcs. The dropping of 103 reestablishes partial circuit l). but whereas formerly it received high elcc tromotive force through terminal 11:2 and armature 100, now it receives medium cle-- tromotive force through terminal 103 and armature 100, armature 110 having opened at the same time that 108 closed. .\lso armature 109 opens at the same time. During the whole movement of the shoe 43 over ramp 5T53. high electroniot-ive force was transmitted. and hence no etTcct of consequence was produced on the car. the action on the car being the same as for the previous engagements of the shoe 43 with the ramps 54.

The car under consideration then proceeds in the block 52 until it engages the first ramp 54. therein. This actuatcs the apparatus on the car. as already described for the ramps 54. and after the shoe 43 leaves said first ramp 54 energy is cut off from said ramp at 101 the same as for ramps 5-1.

reached the sequence of operations same as already described.

Case Passing from a clear block into a caution controlled. block.

Assuming that there is a car ahead in the block 52 and that the car in question is in the block 52, the first ramp 5 and the other ramps 54 in the block 52* will be at medium potential. The car in the bloclr 52 will approach and traverse the ramp 5758 as described in Case 2, but when its shoe 43 touches the first ramp 54 in that bloclr it will receive medium electromotive force and transmit current at that potential through the circuits E and E". This current in circuit E which comprises the impedance 67 will be so weak that when circuit P op-ens at 75, then control relay -66 will drop its armatures 69, and 71. The current in magnet 91 through circuit E which has no impedance corresponding to 67- will be enough to hold up the armatures 92, 93, 9t and of stop relay 909l.

The dropping of the armature 69 opens circuit A so that when the same circuit closes again at 75, magnet 65 will not be reenergized and the armatures 69, 5'0 an 71 will till remain down.

The dropping of the armature 70 opens circuit B extinguishing the green lamp and closes circuit l lighting the yellow lamp, which signifies to the operator that his car is now subject to caution control by a car ahead.

The dropping of the armature 71 opens the circuit C, denergizing solenoid 33, thus leaving the lever 23 free to be displaced by spring 24. as may be permitted by the escapement dog 38.

The raising of the shoe 43 on the ramp 54: closes the contacts 76 energizing the magnet 41 through circuit F. The resulting oscillation of the dog 38 permits the spring 24: to throw the lever 23 clockwise a distance corresponding to a half notch'on the rack bar 36. When shoe 43 leaves the ramp 54:, the spring 39 returns the dog 38, permitting the bar 36 to complete a displacement of one full notch.

As the car proceeds in the block 52 it engages the other ramps 54 in that block successively and each engagement results in a further displacement of the lever 23, each time a distance corresponding to a notch of the bar 36. Thus as the car passes along in the caution controlled block 52", the wedge 19 is advanced step bystep between the rollers 21 and 22, thus lowering the member 20 relatively to the member 16. As in case 1, it is permissible for the operator to run the car with the contacts closed at 62 and with the warning signal W in action. In this condition, it the operator maintains a uniform speed, the her 16 will stay at a uniform height, the lowering of the bar 17 by the advancing wedge 19 will eventually close the contacts 63 and actuate the warning signal it, which will indicate to the operator that unless he reduces his s eed, presently the contacts 6% will be opene. and the emergency brake apparatus EB will be actuated.

Thus the car the caution controlled block 52 will have its speed limit reduced progressively or else the emergency brakes will be applied, and by the time the car up preaches the end of the block it must he going at a safe low speed.

The car in the caution controlled block kills the ramps 5% behind it as described in case 1 for a car in a clear bloclr.

Case 4. Release ram caution control within 0; Mock.

While the car in question is in the block 52 and before it has neared the end of the block, assume that the car ahead leaves the block 52. Thereupon the track relay 55 in block 52 picks up its armature So that whereas the partial circuit l) in bloclr 52* formerly received medium electromotive force from the terminal 103, now gets high electromotive force from the terminal 112.

The next time the car in the block 52 engages a ramp 54 its shoe 43 will get this high electromotive force through circuits E and E and the resulting current in the circuit E will cause the magnet 66 of the control relay 65-66 to pick up its armatures. The picking up of the armature 69 closes circuit A so that direct current magnet 65 thereafter will hold up its armatures. The raising of armature 7O extinguishes the yellow lamp and lights the green lamp, signifying to the operator that he has been freed from control. The raising of thearmature 71 closescircuit C, energizing solenoid 33, and returning lever 23 to its position shown in Fig. 1. During this movement of the lever 23, the rack bar 36 slips by the dog 38, oscillating it rapidly. Thus the spring 18 is permitted to push back the wedge 19, following the pin 29 on the lever 23, and the parts on the car. are restored to the condition assumed in case 1 and progress thereafter will be the same as in case 1.

C ose 5. Passing from a caution controlled block 150 a danger controlled block.

Following case 3, assume that a car ahead is standing in the block 52* and that the car behind in the block 52 goes to the end of that block subject to caution control. llnas' much as the car in the block 52 shunts the associated track relay 55, the armature 100 will be down and the ramp end 57 will receive medium electromotive force. When ill) llli

the shoe 4 engages the ramp end 57, current of medium clectromotive.force flows in 1nagnets 105 and 106 and magnet 105 raises its armature 108. but on account of impedance 10?. magnet 106 does not raise its armatures. A('('O1(li11;j'l shoe -18 gets medium electromotivc l'orce untilit crosses from part 57 to part 58. the latter being dead because of the failure of magnet 100 to pick up its arm t 100. The engagement of the shoe 2, with the ramp T-58 breaks both circuits A and A at. T5 and when shoe 13 reaches ramp end 58 no more alternating currentis received through the circuits E and E. At this time the armatures 69. and T1 of control relay (i566 are down, and now armatures 92. 03, 9-1 and 95 of stop rela) 00-01 will also drop. The dropping oi the armature 92 opens the direct current circuit A so that the last named armatures can only pick up by energization of the alternating current circuit E. The dropping ot the armature 93 deenergizes the solenoid 81 (circuit (ir) permitting "the spring 83 to push the wedge 19 to its limiting position and hold it there. At this time the wedge 19 will have already practically reached that position by the step by step movement of the lever 23 through the block 52". The dropping of the armature 91 closes a multiple branch to circuit t. and energizes solenoid 83. ((ircuit This restores the lever 23 to the position shown in the drawing, the pin 20 sliding across to the right in the slot 28, while spring 88 holds the wedge 19 at its extreme left hand position. When the solenoid 83 has drawn the lever 23 over to the position shown in Fig. 1

the insulating button 89 on lever 28closes the contacts 87, thus closing a circuit through armature 95 (circuit H) which is down at this time. This energizes the. magnet 84.- closing contacts 85' and establishing a stick shunt through magnet 84 (circuitll'). Also the energization of the magnet. 81 raises the armature 86, opening the circuit and deenergizing the solenoid 33. leaving the lever 23 free to be displaced by the spring 24 as may be permitted by the oscillations of the dog 38. The dropping of armature 95 closes a multiple branch of circuit'H (or H) and thereby illuminates the red lamp R. which signifies to the operator that his car is now subjected to danger control.

'ith the apparatus in this condition the shoe 13 leaves the ramp end 58 and the car proceeds in the block 52". which it will be remembered is assumed to be already occupied by a car ahead. The extreme position of the wedge 19 enforces a very low speed on the ear behind, at which sp ed it will crawl through the block 52 until it overtakes the car ahead. l nder the conditions described, I consider itpermissible for the car to enter the block 52 behind another car, because the following car is traveling at such a low speed that it can be readily stopped by the operator as soon as he sees the car ahead, and also because at such low speed the damage of a collision would not be prohibitively serious. Thev part of partial circuit I) in the block 52 behind the car ahead is dead because. the car ahead has opened ari'natures 1.02 and 101 immediately behind it, so that the ramps 54 and 51 that are engaged by the car behind will be dead and none of the armatures on the relays 65-66 and 9091 will pick up.

Each time the shoe 43 engages a dead ramp such as 54, the dog 38 will give an oscillation permitting the spring 24 to stop the lever 23 across clockwise, moving the pin 29 in the slot 28. Inasmuch as the wedge 19 is in its extreme left hand position fully between the rollers 21-22, this will be an idle movement of the lever 23. But as the car proceeds in the block the lever 23 will be advanced the same as it would be if the block were cautioncontrolled instead of danger-controlled.

( 'ase 6'. Release from danger control within a block.

the ramp 54. Thereupon the next time the car behind engages a ramp 54, it finds that ramp energized with current of medium electro-motive force. This current in the current E energizes the magnet 91 sufliciently' to pick up its armatures. ing of the armature 92 closes circuit A so that direct current magnet can hold up the armatures thereafter. The raising of armature 93 energizes solenoid 81 so that it retracts the head 82, permitting the spring 18 to return the wedge 19 as far as will be determined by the pin 29 in the slot 28. The raising of the armature 94; is of no substantial effect at this time for circuit C is already open at 86. Vhen the armature 95 picks up, it opens the stick circuit H, deenergizing the magnet 84 and closing the contacts 86 in readiness for another cycle of operations as described heretofore. The raising of the armature 95 also extinguishes the red lamp R. thus apprizing the operator that he is released from danger control.

It will be remembered that at this time the lever is in an intermediate position. having been stepped across from its initial position at the beginning of the block 52", (Case 5), hence the wedge 19 will now take a position which will be the same as if the The rais-' car had proceeded under caution control to l s m its present location 111' the block. therefter. the car can proceed through the block Sub ect to caution control as described in a Case 3. Thus the departure. of thocar ahead from the same block 52* occupied by the car behind raises the degree of control of the car behind from danger control to caution, control. it while the car behind remains in the same block the car ahead goes on out of the block ahead. the degree of control' for the 7211 behind will be raised another stage. that from caution control to full clear as described in case Case 7. Passim; from a caution coazroY/cd Mode to a caution coat/077ml DZOcZu If the front. wheels of the car behind enter block 52 before the rear wheels of the ear ahead leave said block. then the car hehind has danger control imposed by engagement of its shoe 43 with the ramp 5I 5H between blocks 52 and 52". But if the car ahead stands so that its shoe =13 has passed ramp 5T58 and said train is now in block 52, then rams .51 and 51 in block 52" will be supplied with lflttlltlll'l electromotive force which will impose caution control. so that the car behind will have its control dropped from caution to danger in the interval from ramp 5TT t-. to ramp 51 in block 52", and thereafter raised to caution. lint in this interval the danger control will he a mere continuation of the advanced stage of preceding caution control and a new cycle of caution control will be rcimposed at ramp 5%. (in the other hand. if the rear wheels of the car ahead have left block 52" before the front wheels of the car behind enter that block. then the engagement of shoe 43 of the car behind with ramp 51-58 entering block 52 will release the car behind of cantion control in block 52 until ramp 54 is reached. when such control will be reimposed. The clear control in the interval will be of short duration (from ramp 5l'-5tto ramp 5%),11nd will thereafter shade otf in the initial stages of caution control.

(Mac 8. Passing from (L dang m controlled Noclr t0 (1 (lung c1" COIIf/UZ/(VZ 070/7.

liven if the car behind follows closely all the way through the block so that it gets danger control at the ramps 51. it will nevertheless get caution control at ramp 5T-38. because the end 57 of ramp oi -5H can never be dcadhut will alwa vs get high or medium elect romotive force. in this case medium. Hence the car behind will have caution control from ramp 51-58 to ramp 54 but this will be of such advanced degree as to be the same as a continuation of the danger control. for at this time the lever 23 will have been stepped clear across clockwise from the beginning of block 52.

messes 'Jlhe s-ipacing of the ramps 51 in the blocks will be in accordance with the length and other characteristics of the blocks. Thus for example if the block is down grade and long compared with block 52", the

ramps 5-} in block 52" may be spaced more so widely than ramps 54- in block 52*.

ilimiz-fimzoa 07" Figure i'.'il his shows a modified arrangement of tl apparatus assoi ciatcd with the track. it comprises substantiall} he same apparatus as shown in Fi ure 2 and indicated he the same reference numerals. and in addition it shows the elements designated by the numerals 120 to 1212 inclusive and the letter M.

There is here substantiall Y the same "iarno tial circuit l). which may be energized with high or medium electromotive force according as the block ahead is unoccupied or occupied. that is according as armature is up or down; in addition. there is a partial circuit from terminals 111 and 128 which. when energized, is energized with low electroniotive force (circuit 'llhis is too low to affect the car carried magnets (it; and 91 in partial circuits l5 and lid and too low to affect the track magnets 91 and '96. but sufficient to actuate track magnet 120. This difference of sensitiveness of magnets 97 and 96 compared with 120 ma be determined by the in'ipedance 129.

ll hether circuit D is energized with high or medium electromotive force. in the alosence of a car ahead in the block 52. the engagement of a car shoe 43 with a ramp 51 is the same as for Figure 2. sticking up the armature 98 and killing the ramp 51 by the dropping of armature 101 when the shoe 4% leaves the ramp 5- Also the. magnet 97 picks up and holds up armature 123 opening the branch circuit of magnet 120. Also. after breaking at 102125 the connection with partial circuit D. the part of said partial circuit D in the rear of the train is reconnected to partial circuit M at 102-121. So a single car in the block proceeds through the block. actuating the track apparatus at each ramp 54 in the manner described.

But if a second car follows in the same block (under danger control. of course). it

will find each ramp 51 energized with lowelectromotivc force through contacts 121 102 in the rear of the car ahead and through armature 123 and magnet 120 associated with such ramp The resulting current through magnet- 120 will cause it to pick up its armatures 121 and 122, thus sticking it up at 121 and opening at 122 all of the partial circuit D to the rear of the second car.

lVhen the car ahead engages ramp end 5?, partial circuit D will be cut ofl' at 108-126 from its supply of high or medium electromotive force and will get low electromotive force at 1()8127. This will restore the track apparatus to normal back as far as the ramp immediately behind the second car, but no farther back. Hence a third car behind the second car in the same block will not be released from danger control. At the ramp 51 behind the second car in the block, the low potential current flowing from partial circuits M and D goes through armature 123 and magnet 120 in multiple with magnet 97, annature 99 and magnet 96. When the shoe 43 for this first car leaves ramp 57-58 and armature 108 drops back on contact 126. and partial circuit D gets high or medium electromotive force as far back as the ramp considered, the resulting increased current in the branch path 97, 99 9(3 raises armaturcs 98 and 123 inter alia, thus deenergizing magnet 120 which drops its armatures 121 and 122, and the condition of this apparatus associated with ramp 54 now becomes the same as ifit were behind the first car in the block, and indeed it is now behind the fiist car in the block, for what was the first car in the block has now passed out of the block. The track-way apparatus of Figure 3 will be seen to afford protection for as many as three cars traveling in sequence in one block, even though the second car waits in the block while the first car proceeds out and the thirdcar follows on in. If the trattic conditions should be such as to necessitate it,.then the block lengths, or the rules of trathqor both, can be arranged so that adequate protection will be afforded for a larger number of cars in sequence on the track.

T he relays associated with the track should be properly designed and timed to work in the manner stated, thus for example when an armature 121 is stuck up and an armature 102 ahead is dropped, the magnet 120 should not let go between the break at 124 and the make at 125. For another example. armature 98 should break before armaturcs 99 and 123 make, or the same resultant effect should be accomplished by proper proportion and design. Impedanccs of proper magnitude may be introduced at any point such as 130, 131 and 132.

What I claim is:-

1. In combination, a one way track, a car thereon. a safety appliance for excessive speed on the car. apparatus for controlling said appliance adapted to change progressively under successive influences to impose decreasing speed limitations, a series of ramps along this track, a shoe on the car to engage said ramps in passing, means to condition the ramps alike in groups according to the location of a car ahead on the track, and means on the car responsive to the engagement of the shoe with the ramps and effective to exert successive influences on said apparatus depending upon the condition of said ramps.

2. In combination, a one way track, a car thereon, a safety appliance for excessive speed on the car, a series of ramps along this track, a shoe on the car to engage said ramps in passing, means to condition the ramps alike in groups according to the location of a car ahead on the track, an apparatus on the car for governing said appliance adapted to be changed to impose de creasing speed limitations by the successive engagement of the shoe with the ramps in correspondence with the condition of .the ramps.

3. In combination, a one way track. a car thereon, a safety appliance for excessive speed on the car, a series of ramps along this track, a shoe on the air to engage said ramps in passing, means to condition the ramps alike in groups according to the location of a car ahead on the track, apparatus on the car adapted to be influenced to impose decreasing speed limitations hy the suc cessive engagement of the shoe with the ramps 01 to be restored to its initial high speed condition in accordance with the condition ofthe ramps, and means to actuate said appliance by said apparatus.

4. In combination, a track divided into blocks, a car thereon, a safety appliance for excessive speed on the car, a series of ramps along each block, a shoe on the car to engage said ramps in passing, means to condition the. ramps of a block alike according to the location of a car ahead on the track, apparatus on the car adapted to be actuated progressively by the engagement of the shoe with the ramps in correspondence with the condition of the ramps, and means to actuate said appliance by said apparatus.

5. In a train control system for railroads having tracks divided into blocks each provided with a normally elosedtrack circuit. speed control apparatus on acar adapted to change from an initial condition under suecessive cautionary influences and to enforce progressively lower speeds for the car. said apparatus being restored to its initial condition by a clear influence, trackway devices disposed at intervals in each block and governed by the track circuit of the next block in advance, means on the vehicle cooperating with said trackway devices for transmitting caution or clear influences from the track to the vehicle, depending. upon the presence oi absence of another car in said next block in advance, the trackway devices behind a car in the same block being automatically rendered incapable of transmitting a clear influence irrespective of the presence or absence of a car in the next block in advance, whereby the speed control apparatus on a car will be operated by the trackway devices and will compel a reduction in speed of the car during its. travel through a block while the next block in advance is occupied, but will be automatically restored to its initial condition at any one of the trackway devices when the next block in advance becomes unoccupied.

, 6. In combination, a car,apparatus on the car adapted to be changed from an initial condition under successive influences to impose progressively decreasing speed liinita tions or to be restored to its initial condition by an influence of another character, and a plurality of fixed impulse devices distributed along each block and adapted to transmit to the apparatus on a passing car different iniiucnces depending upon the presence or absence of another car. in the next block in advance, whereby the apparatus on a car will be changed during its progress through a block when the next block in advance is occupied, and will be automatically restored to its initial condition when said next block in advance becomes unoccupied.

7. In combination, a one way track divided into blocks, a car on the track in one of said blocks, means disposed along each block adapted to be conditioned specially in one way in the block behind that occupied by the said car, and another way behind said car in the same block therewith, a car on the track behind, a safety appliance for excessive speed on the car behind, means on the car behind adapted to cooperate with said mea is disposed along each block, and

apparatus on the car behind adapted to actuate said appliance conditionally according to the condition of the means disposed along the block with which the means on the car is in cooperation.

8. In combination, a one way track di vided into blocks, means disposed-at intervals along each block and conditioned alike in one way in the rear of a car in that block and alike in another way in the next block in the rear, a car on the track behind, a safety appliance for excessive speed on the car behind, means on the car behind ada ted to cooperate with said means disposed a ong each block, an apparatus on the car behind adapted to actuate said appliance conditionally according to the condition of the means disposed along the block with which the means on the car is in cooperation.

9. lln combination, a track divided into blocks, means disposed at intervals along each block and automatically caused to as sume ditierent controlling conditions depending upon the presence or absence of a car ahead in the same block or in the next block in advance, a safety appliance for excessive speed on a following car, and c0- operating means on the following car adapted to actuate said appliance in accordance with the controlling condition of said first mentioned means.

10. lln combination, a one way track divided into blocks, a safety appliance for excessive speed on a rear car, means disposed along each block subject to control by a car ahead and adapted to have its condition altered from normal according to whether the car ahead is located in that block or the block next in advance, and cooperating means on the car behind adapted to actuate said appliance conditionally according to the condition of the said means disposed along each block as determined by the relative location of the car ahead.

11. In combination, a one way track, a series of ramps along said track, a car on the track,'mean s specially to condition all said ramps alike to a certain distance in the rear of the Car, a car behind on the track having a shoe to engage said ramps, permissive speed means on the car, and means on the car actuated by the successive engagements of the shoe with the specially conditioned ramps to adjust the permissive speed means step by step to lower and lower speeds.

12. In ombination, a track divided intoblocks, apparatuson a car including means for establishing varying permissive speeds therefor, and means disposed at intervals along each block and adapted when the next block in advance is occupied to cause said apparatus to reduce the permissive speed established thereby step by step, said means also acting to restore said apparatus to its initial condition when the next block in advance becomes unoccupied.

13. In combination, a oneWay track divided into blocks, speed control apparatus on a car adapted to be controlled from the track and enforce varying speed restrictions, and means associated with each block and responsive to the occupancy of a block ahead, said means being adapted to cause the operation of the speed control apparatus in a block when the block ahead is occupied and to relieve the appa-ratus'of such control when said block ahead is vacated, said means behind a car in the same block being rendered ineffective by said car to relieve said. apparatus of its control:

' 1st. lln combination, a one way track divided into blocks, a car thereon, a safety appliance for excessive speed on the car, apparatus on the car to actuate said appli ance, means disposed along each block adapted to be conditioned alike within a block by the occupation of a block ahead and to be conditioned differently in an occui ieaaee pied block behind the point of occupancy thereof, and means on the car adapted'to cooperate with said means disposed along each block thereby to control said apparatus according to the condition of said last mentioned means.

15. in combination, a one way track divided into track circuited blocks, a car thereon, a safety appliance for excessive speed on the car apparatus on the car to actuate said appliance, means disposed along each block adapted to be conditioned by shunting of the track circuit of the block ahead and means on the car adapted to co operate with said means disposed along each block to control said apparatus. said means disposed along each block being adapted to be conditioned further by cooperation therewith of said means on the car.

16. In combination, a one way traclr divided into track circuited blocks, a car thereon, a safety appliance for excessive speed on the car, apparatus on the car to actuate said appliance, means disposed at intervals along each block adapted tohave different conditions, means comprising the track circuits to contribute to determining the condition of said means disposed along the track, means on the car to cooperate with said means disposed along each block to actuate said apparatus and also further to contribute to determining the condition of said means disposed along the track.

17. In combination, a one way track divided into blocks, a car thereon, a safety appliance for excessive speed on the car, apparatus on the car to actuate said appliance, means disposed at intervals along each block, and means on the car to cooperate therewith to actuate said apparatus in accordance with the condition of said means disposed along each block, said means disposed along each block being adapted to be conditioned partly by relative block occupancy by a car and partly by the cooperation therewith of said means on the car.

18. In an automatic train control system for railroads having tracks divided into blocks, each as long as braking distance for the trains traveling over said track, means distributed along the track in each block and put in a different controlling ondition when the block next in advance is occupied or the corresponding block itself is occupied, speed control apparatus on a. car adapted to enforce predetermined speed limits and in-- cluding means selectively responsive to the controlling condition of the said trackway means, said apparatus acting automatically to establish decreasing speed limits as the car travels through a block while the next block in advance is occupied and a fixed minimum speed limit as the car travels through a block occupied by another car ahead, said apparatus responding to the change in the controlling condition of said trackway means after the relative block occupancy changes and being thereby influenced to alter the fixed minimum speed limit to the proper decreased speed limit corresponding to the location of the car in the block.

19. In an automatic train control system for railroads having tracks divided into blocks each at least as long as braking distance for the cars traveling on said track, trackway means for transmitting controlling infiuences to a car at successive control points in each block, said trackway means of each block being put in a caution controlling condition when the next block in advance is occupied and in adanger controlling condition behind another car in the same block; and speed control apparatus on the car influenced by said trackway means and acting to enforce successively lower cautionary speed limits at said control points in a block while the trackway means thereof is in the caution controlling condition, and to enforce a maintained minimum speed limit while said trackway means is in the danger controlling condition. said trackway means and apparatus responding to a change in relative block occupancy to shift from the minimum speed limit to the cautionary speed limit corresponding withothe location of the car in its block.

20. In an automatic train control system for railroads having tracks divided into blocks, each as long as braking distance for the trains traveling over said track, traflic controlled means at intervals along the track in each block and automatically caused to assume different controlling conditions when the next block in advance is not occupied, when said block in advance is occupied, and when the corresponding block itself is occupied respectively; speed control apparatus on a car influenced by said trackway means in accordance with the controlling condition thereof, said apparatus including a speed-responsive device and a changeable permissive speed device and automatically 'acting to impose a predetermined restrictive control of the car when the next block in advance is occupied and a more restrictive control when the corresponding block is occupied, said apparatus being also automatically governed by the trackway means to release the existing control at the next trackway means when the relative block occupancy changes.

21. In a system for governing the movement of railway vehicles over tracks divided into blocks, the combination with impulse devices located at intervals in each block and adapted to have different controlling conditions corresponding to indications of stop. caution and proceed: of means responsive to the presence of a train in the block for governing the caution and proceed controlling conditions of the impulse devices of the block next in the rear; and means associated with each impulse device and responding to the passage of a vehicle thereby for placing that device in the stop controlling condition.

22. In a system for governing the movement of railway vehicles over tracks divided into blocks, the combination with a plurality of impulse devices disposed at intervals along each block, of means for causing said impulse devices of each block to assume a roceed controlling condition when the lock next in advance is not occupied, and means associated with each impulse device and responding to the passage of a vehicle thereby for renderinsaid means ineflective to control that impulse device and the other impulse device of that block in the rear thereof.

23. lln a system for governing the movement of railway vehicles over tracks divided into blocks, the combination with avehicle, of automatic train control apparatus thereon adapted when conditioned for operation to impose decreasing limitations on the speed of the vehicle during its progress through a block, means on the vehicle for imposing a predetermined low speed limitation independently of said apparatus, impulse transmitting means at the entrance to each block for conditioning said apparatus for operation and for rendering said means effective when that block is occupied, and impulse devices disposed at intervals along each block and having their controlling condition dependent upon the presence or absence of another vehicle in that block and in the next hloclr in advance, said impulse devices acting to restore said means to its ineffective condition without allecting said apparatus when the corresponding block ahead hecomes clear while the next block in advance is occupied, said impulse devices also acting to restore said means and said apparatus both to their ineffective condition when neither the corresponding block ahead nor the next block in advance are occupied.

:24. in a systemitor governing the move ment of railway vehicles over tracks divided into blocks, the combination with a vehicle, of automatic train control apparatus thereon adapted when set into operation to change from an initial condition to impose decreasing limitations on the speed otthe I vehicle during its progress through aloloclr,

till

means on the vehicle for imposing a predetermined. low speed limitation independently of said apparatus, and impulse transmitting means partly on the vehicle and partly along the track acting automatically at the entrance to each block when that block is occupied to simultaneously render said means eliective and set said apparatus into operation.

raeaaee 25. In a system for governing the movement of railway vehicles over tracks divided into blocks, the combination with a vehicle, of automatic train control apparatus thereon adapted to control the speed of the vehicle through a block, means for governing the operation of said apparatus in accordance with trailic conditions in the next block in advance, and means set into operation at the entrance to each occupied block for imposing a predetermined low speed limitatio independently of said apparatus.

26. ln an automatic train control system for railroads having tracks divided into blocks each provided with a normally closed track circuit, automatic train control apparatus on a vehicle adapted to enforce speed restrictions, impulse transmitting means partly on the track and partly on the vehicle for transmitting control impulses to the vehicle at various points in its travel through a block, said means being inactive behind a car or train in the same block, and. means controlled by the track circuit of each block for governing the impulse transmit-ting means of the next block in the rear, whereby a vehicle traveling through an unoccupied block will have its train control apparatus rendered active or inactive depending upon the presence or absence of another car or train in the next block in advance, and will continue active as the vehi cle enters an occupied block.

2?. ln an automatic train control system for railroads having tracks divided into blocks, the combination with control means associated with each block and adapted to transmit controlling influences to a vehicle at various points in that block under clear caution or danger tralhc conditions corresponding to the presence or absence of another vehicle in the same block or in the next block in advance, of train control apparatus on a vehicle governed by said control means for regulating the speed thereof under caution trallicconditions, and independently controlled car-carried means for enforcing a predetermined minimum speed under dangerous traffic conditions.

2 8. lln an automatic train control system for railroads having tracks divided into hloclrs, the combination with control means associated With-each block and adapted to transmit controlling influences to a vehicle at various points in that block under clear caution or danger tratlic conditions corresponding to the presence or absence of another vehicle in the same block or in the nexthloclr in advance, of automatic train control apparatus on a vehicle governed by said control means and including a variable speed means changeable from its initial condition to enforce successively lower speed limits under caution tratlic conditions during the progress of the vehicle through a block, and

lild

releases separately controlled means for enforcing a fixed minimum speed under danger traffic conditions, said variable speed means being restored and again set into operation as the vehicle enters an occupied block.

29. In a system for governing the movement of railway vehicles over tracks divided into blocks, the combination with train control equipment on a vehicle comprising permissive speed means changeable from an initial condition to impose varying permissivespeeds, means acting to impose a fixed minimum speed independently of said permi'ssive speed means, and an actual speed device, of means partly on the vehicle and partly along the track for governing said train control equipment in accordance with traffic conditions in the corresponding block and also the next block in advance.

30. In a system for governing the movement of railway vehicles over tracks divided into blocks, the combination with automatic train control apparatus on a vehicle having an initial maximum speed condition and changeable to a plurality of lower speed conditions, of means partly on the vehicle and partly along the track for governing said apparatus at various points in the travel of the vehicle through a block in accordance with traffic conditions in the next block in advance, said control means having a distinctive unfavorable controlling condition behind a car in the same block irrespective of the presence or absence of a car in the next block in advance.

31. In a system for governing the movement of railway vehicles over tracks divided into blocks, the combination with automatic train control apparatus on a vehicle having an active and an inactive condition, of control means partly on the vehicle and partly along the track for transmitting controlling influences for governing said apparatus during the travel of the vehicle through a block dependent upon tratlic conditions in the next block in advance, said control means being non-operative behind a train in the same block irrespective of the presence or absence of a train in the next block in advance.

32. in an automatic speed control system for railway trains on tracks divided into blocks; the combination with a brake com trol apparatus on the vehicle adapted to be influenced from the trackway and acting automatically to enforce any one of a plurality of speed limits which the vehicle cannot exceed without an automatic brake ap plication; means partly on the vehicle and partly on the track effective it the next block in advance is occupied to enforce cautionary speed limits by said brake control apparatus in accordance with the local characteristics of the particular block it is occupying to assure stoppage of the train before reaching the end of this block and to remove such restriction when the next block in advance becomes unoccupied; said means restricting the speed of the train to a low speed limit by said control apparatus in a block occupied by another train ahead, releasing such restriction when said another train leaves this block and passes into the next block and simultaneously therewith enforcing a cautionary speed limit depending upon the position of the train in this block so long as the next block is occupied by said another train.

33. In an automatic system for controlling the speed of railway vehicles on tracks divided into blocks each at least as long as braking distance for the normal running speed of the vehicle, the combination with brake control apparatus 9n the vehicle adapted to be influenced from the trackway and acting automatically to enforce any one of a plurality of continuing cautionary speed limits which the vehicle can not exceed without an automatic brake application, means partly on the vehicle and partly distributed along the track in each block for governing said apparatus at successive points in said block, said means governing the brake control apparatus during the progress of the vehicle through a block so long as the next block in advance is occupied to estab lish successively lower speed limits and to maintain said apparatus in a minimum speed condition in a block occupied by another train ahead. said means responding to a movement of the train ahead out of the next block in advance to change the existing cautionary speed limit to a clear speed limit, and also responding to the movement of the train ahead out of the same block to change the existing minimum speed. limit to the proper cautionary speed limit corresponding to the existing location of the vehicle in that block.

In an automatic train control system for railways divided into blocks, the combination of a permissive speed device on a railway vehicle tending to assume a mini mum permissive speed condition, an actual speed device, a brake-setting appliance adapted to apply the brakes ot' the vehicle if the actual speed exceeds the permissive speed; and means partly on the vehicle and partly along the trackway for counteracting the tendency of said permissive speed device and settingup a plurality of diticrent cautionary speed limits in a caution block dependent upon the progress of the vehicle. and for restoring said permissive speed device: said means acting to rcmnve its counteraction when moving in a block occupied by another train to allow the permissive speed device to assume its minimum. speed condition until said another train moves out of the block, whereby the vehicle will again be limited to the proper caution speed limit depending on its position in the block due to said another train now occupying the block ahead.

35. In an automatic train control system for trains moving on tracks divided into blocks, the combination of vehicle carried apparatus comprising permissive speed device on a railway vehicle tending to assume a minimum permissive speed condition, an actual speed device, a. brake-setting appliance adapted to apply the brakes ot the vehicle it the actual speed exceeds the permissive speed; and of means partly on the vehicle and partly along the trackway for controlling said apparatus, said means under clear trafic conditions maintaining the permissive speed means in its maximum speed condition, allowing the permissive speed to gradually assume lower intermediate speed conditions as the vehicle passes through a block when the next block in advance is occupied, allowing it to assume a minimum speed condition upon entering a block occupied by another train, and again urging said permissive speed device to the proper intermediate speed condition depending on the position of the vehicle in the block when said an her train moves out of said block into the next block ahead.

36. An automatic train control system for railways divided into blocks comprising; vehiclecarri cd means including a permis sivespeed device, an actual speed device, a brake-setting appliance adapted to apply the brakes if the actual speed exceeds the permissive speed, a plurality of independent means tending to cause said permissive speed device to assume a. minimum speed condition, one of which if allowed to be come eflective enforcing an intermediate speed limit, and another if allowed to become etlective enforcing a minimum speed limit; and tratiic controlled means partly on the vehicle and partly along the trackway for transn'iitting control influences to said vehicle-carried means to allow one of said independent means to become etlective when the vehicle moves in a block and the next block in advance thereof is occupied, and allowing nother of said independent means to become effective when the vehicle enters a block occupied by another train ahead.

37. In an automatic train control system for governing the movement of vehicles over tracks divided into blocks, the combination of two independent means on the vehicle which it effective tend to cause an automatic application of the brakes if the vehicle exceeds certain predetermined speed limits, and of trackway means located at successive points throughout each block and cooperating with car-carried means for preventing both of said independent means from becoming efiective under clear t-raflic conditions ahead, allowing one of said independent means only to become ellective when said vehicle is traveling in a. block and the next block in advance is occupied, and for allowing both of said independent means to become effective when said vehicle moves in a block occupied by another train ahead.

38. Car-carried apparatus for automatic train control systems comprising, two independent means tending to assume a low permissive speed condition, one of said means being capable only to assume such con= dition gradually with the progress of the vehicle, means for automatically applying the brakes of the vehicle it the speed of the vehicle exceeds the lower speed condition set up by either of said two means, and two independent normally energized devices-each opposing the tendency of one of said independent means under normal clear traffic conditions ahead, whereby the deenergization of one of said devices gradually restricts the speed the vehicle may assume without incurring an automatic application of the brakes, and the deenergization of the other device immediately restricts the speed of the vehicle to correspond with said predetermined low speed condition.

39. lln an automatic train control system for governing vehicles moving on tracks divided into blocks; the combination of a permissive speed device on the vehicle capable of assuming a pluralityot permissive speed conditions and tending to assume its lowest permissive speed condition, an actual speed device, and meansgfor automatically applying the brakes of the vehicle it the actual speed exceeds the permissive speed; and apparatus partly on the vehicle and partly along the track for allowing said permissive speed device to assume a condition depen dent on the position of the vehicle in the block it the next block in advance is occupied, allowing it to assume said lowest speed condition it the block is occupied by another train ahead, again restoring said permissive speed device to a condition dependent on the position of the vehicle in such block when said another train moves out of said block into the next block in advance, and again restoring it to its maximum speed condition when said another train moves out of the next block in advance into the second block in advance.

d0. lln an automatic train control system for governing vehicles moving on tracks divided into blocks; the combination of a permissive speed device on the vehicle capable of assuming a plurality of permissive speed conditions and tending to assume its lowest per niissive speed condition, an actual speed device, and means for automatically applying the brakes of the vehicle it the actual spee exceeds the permissive speed; means partly on the vehicle and partly along the trackits is way and including traclrway apparatus effective at a lurality of points along the track in each lock for setting up predator-- mined cautionary speed limits by said permissive, speed device at said points if the block in advance'is occupied, and for again urging the permissive speed device to its maximum s eed condition when the block in advance comes clear, and other trackway means including said trackway apparatus for setting up a minimum speed limit b said device when the same'block is occu-' pied by "another train ahead and for setting up the proper cautionary speed limit by said device depending on the position of the train in the block when saidanothe'r train passes out of said same block into the next block ahead.

41. In an automatic train control and cab signalin system for railways having tracks divided mto blocks, the combinationof signaling means adapted to indicate clear, caution and danger on the railway vehicle; and means partly on the vehicle and partly along the track and independently effective through a plurality of sections in each block for indicating caution when the block in advance of the train is occupied, for indicating dan er when the same block is occupied b anot er train ahead, and for indicating 0 car when the same block is not occupied by another train ahead and when the} next blockin advance is clear; and brake control apparatus for controllingthe movement of the train in accordance with the indications of said signaling means.

42. In anfautomatic traincontrol system for railways having tracks a divided into track-circuited blocks, the combination with vehicle carried apparatus comprising a changeable permissive speed device adapted to be changed during the rogress of the vehicle through a block an thereby set up decreasing permissive speed'limits, a minimum permissive speed device, an actual speed device, and an appliance forapplying the brakes of the vehicle if the actual speed exceeds the lowest permissive speed set up by said two permissive speed devices;-of in.- fiuence communicating means-partly on the .vehicle and partly on the trackway "for initiating and restoring'to an initial condition said changeable permissive speed device and for rendering active or inactive said minimum permissive speed device, said means acting to initiate the changeable permissive speed device on, the vehicle and set up decreasing speed limits during the progress of the vehicle through a caution block next in the rear of an occupied block and to restore said changeable device at various points in mid caution block if the next block in advance becomes unoccupied said means rendering said minimum s eed device active on the vehicle while in a anger block occupied by another train ahead and inactive if said another train ahead leaves that block.

' 43. In an automatic .train control system.- for railways having"tracks' divided into blocks, the combination with a changeable permissive speed device on a vehicle con-- trollable to automatically" change to lower speed conditions during the progressof the vehicle, said device bein governed vfrom the trackway and beinginitiated near the entrance to each danger block occupied by another train ahead and near the entrance of each caution block in the rear of an occupied block and again being. reset at the end of either of such blocks, of aminimumpe'r missive speed device, an actual speed device operated by the wheels of the vehicle, and

a brake-setting appliance for applying thebrakes if the actual speed exceeds the lowest permissive speed set up by either of said,

for railways having tracks divided into track-circuited blocks, the combination with vehicle carried apparatus comprisinga changeable permissive speed device adapted to be changed during the progress of the vehicle through a block and thereby set up decreasing permissive wan: limits, a minimum permissive speed device, an actual speed device, and an appliance for applyin t e-brakes of the vehicle if the actual spec. exceeds the lowest permissive speed set in by said-two permissive speed devices; tr c controlled means for governing said permissive speed devices from the trackway, said means causing operation of said changeable permissive speed device to set up dec in s limits during the progress of the ve ice through a caution block next in the rear of an occupied block, restoring said changeable device to normal at various oints in said caution block if. the next lock in advance becomes unoccupied, restori to normal said changeable device at the exit end of the caution block. irrespective of to conditions, causing operation of said changeable device in a dan er block occupied by another train ahead an rendering the minimum sp ed device efiective in such danger block.

4:5. in an automatic train control system for railroads havin; tracks divided into blocks each provid .1 with a track circuit and at least as long as braking doe for the trains traveling over the trackway, the combination with brake control apparatus on a vehicle including changeable permis sive speed means and separate caution and danger control devices therefor, of traffic controlled means for governing said control devices for the permissive speed means from the trackway at various points in each caution block and in each danger block, said traflic controlled means governing the cantion control device during the progress of the vehicle through a caution block to set up different speed limits and automatically removing said speed limits if the caution block changes to a clear block, said traflic controlled means also renden'ng the danger control device active in a danger block to impose a predetermined minimum speed limit and automatically rendering said danger control device inactive in a danger block if that block changes to caution or to clear,

said means also restoring and operating the danger control device in a danger block as in a caution block and thereby providing the proper caution speed limit for the vehicle corresponding to its existing position in the block in case the block changes from danger to caution and the minimum speed restriction is removed.

46. In a train control system for regulating the speed of vehicles under caution and danger traffic conditiQns during their progress through blocks, speed control apparatus on a vehicle controllable from the trackway to determine restricted speed limits which the vehicle cannot exceed Without an automatic brake application, and means controlled by the presence or absence of other trains ahead and having different influences upon a passing-vehicle dependent upon its location in the particulariblock for governing said apparatus on a passing vehicle, said means actm to cause said-apparatus to enforce a pre etermined minimum speed limit during the progress of the vehicle through the danger block occupied by another train ahead and automatically change from said minimum speed to a caution speed limit corresponding to the location of the vehicle in the block in case the train ahead moves out into the next block in advance.

47. In a system for automatically regulating the movement of vehicles through blocks each at least as long as braking distance for the normal running speed of the vehicles, brake control apparatus on a vehicle governed from the trackway and acting automatically to prescribe any one of a plurality of restricted speed limits which the vehicle cannot exceed without an automatic brake application and which correspond to the character of control influences communicated from the trackway, means partly on the vehicle and partly on the track for governing said apparatus in acreeaaee cordance with traffic conditions and also dependent upon the location of the vehicle in a block, said means automatically establishing or removing clear or caution speed limits at predetermined control points in a block-depending upon the absence or presence respectively of another train in the block next in advance, said means alsoautomatically establishing a predetermined minimum s eed limit for the vehicle in a block occupied by another train ahead and changing said minimum speed limit to a clear or a caution speed limit as said another train' ahead advances from the same block or the next block in advance.

48. In an automatic train control system, the combination with brake control apparatus on the vehicle comprising normally energized circuits and devices and tending to. assume a minimum speed condition in which the brakes are automatically applied if the vehicle exceeds a predetermined minimum speed, trackway means including a source of current and circuits selectively opened and closed dependent on trathc conditions ahead for preventing the brake control apparatus on a passing vehicle from changing to its minimum speed condition during its progress through a clear or a caution block, said trackway means being ineffective in the rear of a train in the same block irrespective of the presence or absence of other trains in the block next in advance.

49. A system-of automatic train control for railway vehicles travelin on tracks divided into blocks each provi ed with a normally closed track circuit and each at least as long as braking distance for the normal running speed of the vehicles for the re spective blocks under clean trailic conditions, said system comprising cooperating means, on' the vehicle and on the trackway controlled by the track circuits of the several blocks for enforcing variable speed limitsin each caution block next in the rear of an occupied block and a continuing minimum speed limit throughout an occupied block, said means causing automatic change at any one of a plurality of intermediate points in a block from the minimum speed limit to the caution speed limit corresponding to the location of the vehicle in that block and also removing the existing caution speed limit as the relative block occupancy changes. I

50. A system of automatic train control for railway vehicles traveling on tracks divided into blocks each provided with a norm-allyjclosed track circuit and each at least as long as braking distance for the normal running speed of the vehicles for the respective blocks under clear trafiic conditions, said system comprising car apparatus; trackway means controlled by the track ciramazes cuits of the several blocks for governing said apparatus automatically, said apparatus and trackway means cooperating to enforce a predetermined continuing minimum speed limit for the vehicle while it is in a block occupied by another vehicle ahead and to cause automatic change of the minimum speed limit to a higher speed limit while the vehicle is in an intermediate portion of said occupied block if the other vehicle ahead advances wholly into the next block in advance.

51. In a system of automatic speed control for railway vehicles on tracks divided,

into blocks each at least as long as bra-king distance for the normal running speed of the vehicles, the combination with brake control apparatus on the vehicle operable to establish at least two different persisting speed limits, one minimum speed-limit being suitable for the movement of the vehicle in a block occupied by another train ahead, and the other speed limit being suitable to regulate the movement of the vehicle through a portion of a caution block, and trackway means for governing said apparatus at selected control points along the track to establish said speed limits at least two separated points in a caution block, said trackway means automatically causing the removal of such speed limits in a caution block when it changes to a clear block but being ineffective to remove such speed limits in a block behind another train in the same block irrespective of the presence or absence of other trains in the next block in advance thereof.

52. In a system of speed control for railway vehicles, in which predetermined cautionary and danger speed limits are automatically established and removed at various points in a given block as traffic conditions change, trackway means for communicating control influences to a vehicle during its progress through a block, and trafiic controlled means for governing. said trackway means in accordance with the presence or absence of trains in the next block in advance, said trackway means being inefi'ective behind a train in the same block irrespective of its control by said t-rafiic controlled means.

municating to the vehicle distinctive electrical controlling influences, and means for selectively governing said trackway circuits of each block: by the track circuit of the block next in advance, said trackway circuits irrespective of their control being automatically rendered incapable of communicating influences to a vehicle behind another train in the same block.

'54. A system of automatic train control for railroads having tracks divided into track-circuited blocks each at least as long as thebraking distance for the speed of vehicles entering said respective blocks under clear traffic conditions, said system comprising automatic brake controlling means on the vehicle cooperating with trackway means governed by the track circuits of said blocks to enforce automatically a plu rality of speed limits in a block dependent on the braking distance to. the end of that block if such block is ina caution condition due to the presence of another vehicle in the next block in advance, said cooperating means also automatically enforcing a continuing minimum speed limit throughout each block occupied by, another vehicle ahead, said means on the vehicle and on the trackway cooperating under the control of the track circuits to change automatically the minimum speed limit in a block to the caution speed limit corresponding to the location of the vehicle in that block at that time or to remove all caution speed limits While the vehicle is in the intermediate portion of a block, whenever the block next in advance or the same block respectively become unoccupied.

In testimony whereof I aliix my signature.

CARL A. RICHMOND. 

